Google IAM Policy Troubleshooter says allowed, but a storage request still fails

0 reputation · 18 Nov 2021, 06:55 UTC

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A service’s storage request is denied. In this illustrative case, Policy Troubleshooter reports that the named principal has the permission on the resource. The team has not checked whether the actual call crosses a VPC Service Controls boundary. Does the allowed result settle the whole access question?

Environment

Editorial worked example. See the question for the scenario and assumptions.

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It settles only what the tool evaluated with the supplied inputs. Confirm the actual caller, resource, permission and relevant request context first. Policy Troubleshooter does not diagnose VPC Service Controls violations, and its documentation also describes limits involving Cloud Storage ACLs.

If those inputs match, investigate the separate boundary using the appropriate service diagnostics or violation analyzer. Adding a broader IAM role may not change a perimeter violation and can unnecessarily expand permissions. Keep the policy finding and the request outcome as separate observations until the complete path is explained.

Google IAM Policy Troubleshooter says allowed, but a storage request still fails

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